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在KSQL中使用“group by”时,如何获取分区键或其他列?

ksql kafka-consumer-api apache-kafka

Shakeel · 技术社区 · 6 年前

group by 我的查询中的表达式。

从主题创建流

CREATE STREAM events_stream \
      ( \
     account VARCHAR, \
     event_id VARCHAR, \
     user_name VARCHAR, \
     event_name VARCHAR, \
     source VARCHAR, \
     message VARCHAR, \
     timestamp STRUCT<iMillis INTEGER>) \
    WITH (KAFKA_TOPIC='console_failure', VALUE_FORMAT='JSON');

从上面的流创建表。

ksql> CREATE TABLE events_table AS \
      SELECT source, count(*) \
      FROM events_stream \
      WINDOW TUMBLING (SIZE 60 SECONDS) \
      WHERE account = '1111111111' \
                  GROUP BY source \
                  HAVING count(*) > 3;

生成此消息4次。

ip="10.10.10.10"

data = {
        "account": "1111111111",
        "event_id": "4cdabe46-690d-494a-a37e-6e455781d8b4",
        "user_name": "shakeel",
        "event_name": "some_event",
        "source": "127.0.0.1",
        "message": "message related to event",
        "timestamp": {
            "iMillis": 1547543309000
             }
        }

producer.send('console_failure', key='event_json', value=dict(data)

这一切如期而至!

ksql> select * from events_table;
1550495772262 | 10.10.10.10 : Window{start=1550495760000 end=-} | 10.10.10.10 | 4
ksql>

使用后,我了解可能是我们在使用时无法获取其他列 分组依据 陈述。

ksql> CREATE TABLE events_table1 AS \
>      SELECT source, event_id, \
>               count(*) \
>     FROM events_stream \
>     WINDOW TUMBLING (SIZE 60 SECONDS) \
>      WHERE account = '1111111111' \
>                  GROUP BY source \
>                  HAVING count(*) > 3;
Group by elements should match the SELECT expressions.
ksql>

我们可以通过重新设置流的密钥来实现这一点吗?

阅读后 this event_id 字段,但不确定如何在陈述。

ksql> CREATE STREAM events_stream_rekey AS SELECT * FROM events_stream PARTITION BY event_id;

 Message
----------------------------
 Stream created and running
----------------------------
ksql>
ksql> SELECT ROWKEY, EVENT_ID FROM events_stream_rekey;
4cdabe46-690d-494a-a37e-6e455781d8b4 | 4cdabe46-690d-494a-a37e-6e455781d8b4
ksql>

ksql> CREATE TABLE  events_table2 AS \
>      SELECT source, \
>               count(*), \
>     WITH (KAFKA_TOPIC='EVENTS_STREAM_REKEY', VALUE_FORMAT='JSON', KEY='event_id'),
>     WINDOW TUMBLING (SIZE 60 SECONDS) \
>      WHERE account = '1111111111' \
>                  GROUP BY source \
>                  HAVING count(*) > 3;
line 1:70: extraneous input 'WITH' expecting {'(', 'NOT', 'NO', 'NULL', 'TRUE', 'FALSE', 'INTEGER', 'DATE', 'TIME', 'TIMESTAMP', 'INTERVAL', 'YEAR', 'MONTH', 'DAY', 'HOUR', 'MINUTE', 'SECOND', 'ZONE', 'CASE', 'PARTITION', 'STRUCT', 'REPLACE', 'EXPLAIN', 'ANALYZE', 'FORMAT', 'TYPE', 'TEXT', 'CAST', 'SHOW', 'TABLES', 'SCHEMAS', 'COLUMNS', 'COLUMN', 'PARTITIONS', 'FUNCTIONS', 'FUNCTION', 'ARRAY', 'MAP', 'SET', 'RESET', 'SESSION', 'DATA', 'IF', '+', '-', '*', STRING, BINARY_LITERAL, INTEGER_VALUE, DECIMAL_VALUE, IDENTIFIER, DIGIT_IDENTIFIER, QUOTED_IDENTIFIER, BACKQUOTED_IDENTIFIER}

KSQL版本详细信息:CLI v5.1.0,服务器v5.1.0

--------------------------复制步骤--------------------------

制片人剧本

import time
import uuid
from kafka import KafkaProducer
from json import dumps

producer = KafkaProducer(bootstrap_servers=['localhost:9092'],
                         value_serializer=lambda x:
                         dumps(x).encode('utf-8'))

for i in range(1, 5):
    time.sleep(1)
    data = {
        "account": "1111111111",
        "event_id": str(uuid.uuid4()),
        "user_name": "user_{0}".format(i),
        "event_name": "event_{0}".format(i),
        "source": "10.0.9.1",
        "message": "message related to event {0}".format(i),
        "timestamp": {
            "iMillis": int(round(time.time() * 1000))
        }
    }
    time.sleep(2)
    producer.send('testing_topic', value=data)

打开从测试主题(使用普通消费者脚本)。

{'account': '1111111111', 'event_id': 'c186ba8a-2402-428a-a5d8-c5b8279e14af', 'user_name': 'user_1', 'event_name': 'event_1', 'source': '10.0.9.1', 'message': 'message related to event 1', 'timestamp': {'iMillis': 1551296878444}}
{'account': '1111111111', 'event_id': '4c45bff7-eb40-48a8-9972-301ad24af9ca', 'user_name': 'user_2', 'event_name': 'event_2', 'source': '10.0.9.1', 'message': 'message related to event 2', 'timestamp': {'iMillis': 1551296881465}}
{'account': '1111111111', 'event_id': '4ee14303-e6d1-4847-ae3d-22b49b3ce6eb', 'user_name': 'user_3', 'event_name': 'event_3', 'source': '10.0.9.1', 'message': 'message related to event 3', 'timestamp': {'iMillis': 1551296884469}}
{'account': '1111111111', 'event_id': '3c196ac5-9559-4269-bf51-95b78ce4ffcb', 'user_name': 'user_4', 'event_name': 'event_4', 'source': '10.0.9.1', 'message': 'message related to event 4', 'timestamp': {'iMillis': 1551296887472}}

预期结果 :如果消息包含相同的 source 在窗口时间后30秒内的地址 account 然后我想马上完成消息(我的案例中的第四条消息如下所示)。使用KSQL可以实现这一点吗?

{'account': '1111111111', 'event_id': '3c196ac5-9559-4269-bf51-95b78ce4ffcb', 'user_name': 'user_4', 'event_name': 'event_4', 'source': '10.0.9.1', 'message': 'message related to event 4', 'timestamp': {'iMillis': 1551296887472}}

0 回复 | 直到 6 年前

Andrew Coates 6 年前

除了罗宾的回答,这个错误:

line 1:70: extraneous input 'WITH' expecting {'(', 'NOT', 'NO', 'NULL', 'TRUE', 'FALSE', 'INTEGER', 'DATE', 'TIME', 'TIMESTAMP', 'INTERVAL', 'YEAR', 'MONTH', 'DAY', 'HOUR', 'MINUTE', 'SECOND', 'ZONE', 'CASE', 'PARTITION', 'STRUCT', 'REPLACE', 'EXPLAIN', 'ANALYZE', 'FORMAT', 'TYPE', 'TEXT', 'CAST', 'SHOW', 'TABLES', 'SCHEMAS', 'COLUMNS', 'COLUMN', 'PARTITIONS', 'FUNCTIONS', 'FUNCTION', 'ARRAY', 'MAP', 'SET', 'RESET', 'SESSION', 'DATA', 'IF', '+', '-', '*', STRING, BINARY_LITERAL, INTEGER_VALUE, DECIMAL_VALUE, IDENTIFIER, DIGIT_IDENTIFIER, QUOTED_IDENTIFIER, BACKQUOTED_IDENTIFIER}

是指你的WITH子句放错了地方。正确的模式是:

CREATE TABLE <table name> WITH(...) AS SELECT ...

你的陈述如下:

ksql> CREATE TABLE events_table2
>     WITH (KAFKA_TOPIC='EVENTS_STREAM_REKEY', VALUE_FORMAT='JSON', KEY='event_id'),
>     AS
>     SELECT source, count(*),
>     WINDOW TUMBLING (SIZE 60 SECONDS)
>      WHERE account = '1111111111'
>                  GROUP BY source
>                  HAVING count(*) > 3;

Robin Moffatt 6 年前

消息本身实际上告诉了您问题:)

Group by元素应该与SELECT表达式匹配。

source 在里面 二者都 SELECT 和 GROUP BY :

ksql> SELECT source, count(*) \
>      FROM events_stream \
>      WINDOW TUMBLING (SIZE 60 SECONDS) \
>      WHERE account = '1111111111' \
>                  GROUP BY source \
>                  HAVING count(*) > 3;
127.0.0.1 | 4
^CQuery terminated

若要添加其他列,请确保将它们添加到也:

ksql> SELECT source, event_id, count(*) \
>      FROM events_stream \
>      WINDOW TUMBLING (SIZE 60 SECONDS) \
>      WHERE account = '1111111111' \
>                  GROUP BY source, event_id \
>                  HAVING count(*) > 3;
127.0.0.1 | 4cdabe46-690d-494a-a37e-6e455781d8b4 | 4

编辑以回答更新的问题

我认为在SQL(或KSQL)中不可能[容易]做到这一点。您可以通过在聚合操作中包含时间戳来实现类似的功能,例如:

CREATE TABLE source_alert AS \
SELECT source, COUNT(*), MAX(timestamp) \
FROM event_stream WINDOW TUMBLING (SIZE 60 SECONDS) \
GROUP BY `source` \
HAVING COUNT(*)>1

然后获取结果表并连接到事件流:

SELECT * \
 FROM event_stream e \
      INNER JOIN \
      source_alert a ON e.source=a.source \
WHERE e.timestamp=a.timestamp